In 1962, just as The Beatles began their rise to pop superstardom, Dick Denney, the chief design engineer for Vox amplifiers, created a special treble boost circuit that could be retrofitted into existing Vox AC-30s. There really wasn’t much magic involved, as the modification simply boosted high-frequency information by 30dB at 10kHz. No guitar amp back then could actually reproduce such hot treble, but the resulting sound was integral in creating the legendary Vox “chime”. At that time, most music was being heard by the public on AM radios, so anything that had a bit of extra high end or edge sounded amazing. Vox soon began building AC-30s with the treble boost circuit built in, and simply called it the “Top Boost” model. Vintage AC-30s with the Top Boost circuitry are among the most sought-after amps ever made.